Textile-based electrodes consisting of electrically conductive wires surrounded by a region of electrically nonconductive textile fibers can be integrated with a wearable article, such as a garment. The wearable article can be adapted to receive or transmit electrical impulses to or from the wearer and, in turn, to or from an electrical device. The patent document WO 01/02052, assigned to Bekaert, discloses such a wearable article.
Wearable textile-based sensors for sensing or otherwise reporting the heart rate (the pulse) of the wearer are disclosed in patent document WO 02/071935, assigned to RTO Holding OY.
Patent document WO 03/094717, assigned to Koninklijke Philips Electronics NV, discloses a textile article that is provided with a region of skin contacting electrodes that are fully integrated within a textile article. The disclosed textile article takes the form of a “bra or a ladies top,” which is otherwise electrically nonconducting. The article is provided with partially overlapping layers of electrically conductive material and electrically insulative material arranged to partially cover and electrically isolate the electrically conductive material.
Patent document WO 2004/006700, assigned to Tefron Ltd., discloses a circularly knit garment having an inner surface electrically-conductive region disposed close to the wearer's skin. The inner electrically-conductive region cooperates to conduct electrical signals to an outerlying electrically-conductive region. Such electrical signals may include the heart rate coming from the wearer or an electro-stimulation means going to the wearer.
Each of these patent documents relates an objective to provide an electrically-conductive region, which can function as an electrode integrated with a garment, a belt, or other wearable article of traditional textile construction. Generally, these patent documents disclose an electrically-conductive region that is otherwise electrically isolated from the remainder of the garment or wearable. Furthermore, these patent documents disclose placing at least one electrically-conductive region of the garment in close contact with the skin of the wearer. As a result, the electrode, formed by this electrically-conductive region in contact with the skin, provides a pick-up point for electrical signals generated within the corpus of the wearer. Alternatively, such an electrode provides a point of contact on the skin to receive an electrical signal generated externally to the wearer. In summary, these patent documents provide means to communicate electrical signals to or from the corpus of a garment wearer.
In addition, these patent documents also generally disclose at least a second textile electrode. More often, the second electrode is integrated with the garment and located at or near an exterior surface of the garment. The second electrode can also be advantageously placed overlying the electrode in skin contact, while also having a portion of the garment's electrically insulating materials of construction therebetween. Where an electrical connection between the electrode(s) in skin contact and the exterior electrode(s) is desired, such connection can be established using metallic wires. Alternatively, the skin contact electrode can be folded over in such a manner as to form the exterior surface electrode continuously.
Where an electrical connection between a garment-integrated electrode in skin contact with the wearer and a garment-integrated exterior electrode is established using metallic wires, certain limitations may exist. Such limitations can be present, for example, when biophysical monitoring via electrical contact with the corpus is desired. These limitations, for example, may include the difficulty of making metallic wires part of a traditionally fabricated textile due to the fragility and durable flexibility of metal wires.
Similarly, other configurations may suffer certain limitations. For example, configurations incorporating “folded over” and partially overlapping layers of electrically conductive material (with electrically insulative material arranged to electrically isolate the electrically conductive material) may severely limit the freedom to design the placement of electrodes integrated with a garment or textile article.
Accordingly, there exists a need to provide a textile-based electrode capable of overcoming one or more of the deficiencies of the prior art.